How would you know that? Did you use something like the Kill-A-Watt plug or you measured the voltage and current separately, or with a wattmeter?
Also, is the 40 W reduction when listening to music for 2 channel stereo and is for peak values (seem very high if that's average value)? Thank you.
I have a smart plug to control my audio-video equipment cabinet. It also measures the total power consumption. There is a base load of about 20W (cable modem/router). I've to disaggregate the loads "by hand" so the per-load accuracy is likely not very good
When listening music with the AVR (2-channel stereo, TV off, no external amplification), the total average power consumption of the cabinet was around 90-100W if memory serves (with external amplification, it is now around 115W).
When listening through the AHB2 and a dedicated streamer (Bluesound Node) and external DAC (Topping E50), the total average power consumption is 48W (pretty constant during the last hour or so). Discounting the base load, the music gear accounts for only 28W: I guess 20-23W for the AHB2, the rest for the streamer and the DAC.
My 40W reduction stems from 90W down to about 48W… the AVR per se consumes more like 70-80W in average (in 2-channel stereo and with video stream off): its amplification channels are always biased even if not used (cannot turn them off without turning off the pre-out AFAIK) and, then, HDMI and DSP chips consume a fair bit of power.
Hopefully that clarifies things.